Oh so what would you do? I am fully self funded lesuire traveller and average 45 nights a year. In past years had added a few bonus nights to make up a platinum year. Last year after being injured had to cancel all my stays after 26 nights and therefore will drop to Gold after Feb 28.
I value lounge access the most as I now have limited mobility due to the accident. At the end of the day I am buggered.

So do I self fund an extra 4 nights this year at a cost of 1000 USD (we have limited Marriott properties where I live) nad no access to Marriott credit cards or status match to Hilton, and easily meet the Diamond criteria? If I go for platinum with Marriott this year there will be no lounge access for the whole year as I literally will make it on the last stay of the year. With Hilton I will get it on the last few stays and still requalify for Marriott gold due to what I have locked in.

My sense is the lounge access for HIlton Diamond is time limited due to their changes late last year so that is prompting my thinking as well

Genuinely asking what would you do in this situation?